I agree about running the risks of a protracted study regimen. I took the GMAT the first time around over a year ago after a 3 month study period. I felt ready but got a 640, well below the 700+ score I was hoping for. The test was too intimidating and I choked. I got really dissapointed and took some time off, deciding to postpone going to school for another year.
So the second time around studied for a month and a half. Instead of casually doing questions here and there this shorter study period allowed a full immersion in the material. I studied on my lunch breaks, at the train station, and every night when I got home. Do not get worried by the results of the practice tests concentrate more on getting used to working in the time constraints of the test. After every test go back an and review what you did wrong. A clear pattern emerged for me, exponents, perm/comb, and mixture problems were always a problem for me.
If you have a weak point in a certain area pound on it. I mean really pound on it. Make sure you understand how right answers are derived.
Do not look at the answer and say "doh!" then move on. The concepts in the math forum are identical to those on the test. Your appetite for practice problems needs to be insaitable.
I wish you guys good luck and good studying. This forum is an unbelieveable asset and I wish I had found it sooner. The biggest piece of advice I could give is to take full advantage of the stellar help available here.
Good luck and kick some butt.
Brendan.